drivers/cpuidle/sysfs.c

   1 /*
   2  * sysfs.c - sysfs support
   3  *
   4  * (C) 2006-2007 Shaohua Li <shaohua.li@intel.com>
   5  *
   6  * This code is licenced under the GPL.
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/cpuidle.h>
  11 #include <linux/sysfs.h>
  12 #include <linux/cpu.h>
  13
  14 #include "cpuidle.h"
  15
  16 static unsigned int sysfs_switch;
  17 static int __init cpuidle_sysfs_setup(char *unused)
  18 {
  19         sysfs_switch = 1;
  20         return 1;
  21 }
  22 __setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
  23
  24 static ssize_t show_available_governors(struct sysdev_class *class,
  25                                         char *buf)
  26 {
  27         ssize_t i = 0;
  28         struct cpuidle_governor *tmp;
  29
  30         mutex_lock(&cpuidle_lock);
  31         list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
  32                 if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2))
  33                         goto out;
  34                 i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
  35         }
  36
  37 out:
  38         i+= sprintf(&buf[i], "\n");
  39         mutex_unlock(&cpuidle_lock);
  40         return i;
  41 }
  42
  43 static ssize_t show_current_driver(struct sysdev_class *class,
  44                                    char *buf)
  45 {
  46         ssize_t ret;
  47
  48         spin_lock(&cpuidle_driver_lock);
  49         if (cpuidle_curr_driver)
  50                 ret = sprintf(buf, "%s\n", cpuidle_curr_driver->name);
  51         else
  52                 ret = sprintf(buf, "none\n");
  53         spin_unlock(&cpuidle_driver_lock);
  54
  55         return ret;
  56 }
  57
  58 static ssize_t show_current_governor(struct sysdev_class *class,
  59                                      char *buf)
  60 {
  61         ssize_t ret;
  62
  63         mutex_lock(&cpuidle_lock);
  64         if (cpuidle_curr_governor)
  65                 ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
  66         else
  67                 ret = sprintf(buf, "none\n");
  68         mutex_unlock(&cpuidle_lock);
  69
  70         return ret;
  71 }
  72
  73 static ssize_t store_current_governor(struct sysdev_class *class,
  74                                       const char *buf, size_t count)
  75 {
  76         char gov_name[CPUIDLE_NAME_LEN];
  77         int ret = -EINVAL;
  78         size_t len = count;
  79         struct cpuidle_governor *gov;
  80
  81         if (!len || len >= sizeof(gov_name))
  82                 return -EINVAL;
  83
  84         memcpy(gov_name, buf, len);
  85         gov_name[len] = '\0';
  86         if (gov_name[len - 1] == '\n')
  87                 gov_name[--len] = '\0';
  88
  89         mutex_lock(&cpuidle_lock);
  90
  91         list_for_each_entry(gov, &cpuidle_governors, governor_list) {
  92                 if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
  93                         ret = cpuidle_switch_governor(gov);
  94                         break;
  95                 }
  96         }
  97
  98         mutex_unlock(&cpuidle_lock);
  99
 100         if (ret)
 101                 return ret;
 102         else
 103                 return count;
 104 }
 105
 106 static SYSDEV_CLASS_ATTR(current_driver, 0444, show_current_driver, NULL);
 107 static SYSDEV_CLASS_ATTR(current_governor_ro, 0444, show_current_governor,
 108                          NULL);
 109
 110 static struct attribute *cpuclass_default_attrs[] = {
 111         &attr_current_driver.attr,
 112         &attr_current_governor_ro.attr,
 113         NULL
 114 };
 115
 116 static SYSDEV_CLASS_ATTR(available_governors, 0444, show_available_governors,
 117                          NULL);
 118 static SYSDEV_CLASS_ATTR(current_governor, 0644, show_current_governor,
 119                          store_current_governor);
 120
 121 static struct attribute *cpuclass_switch_attrs[] = {
 122         &attr_available_governors.attr,
 123         &attr_current_driver.attr,
 124         &attr_current_governor.attr,
 125         NULL
 126 };
 127
 128 static struct attribute_group cpuclass_attr_group = {
 129         .attrs = cpuclass_default_attrs,
 130         .name = "cpuidle",
 131 };
 132
 133 /**
 134  * cpuidle_add_class_sysfs - add CPU global sysfs attributes
 135  */
 136 int cpuidle_add_class_sysfs(struct sysdev_class *cls)
 137 {
 138         if (sysfs_switch)
 139                 cpuclass_attr_group.attrs = cpuclass_switch_attrs;
 140
 141         return sysfs_create_group(&cls->kset.kobj, &cpuclass_attr_group);
 142 }
 143
 144 /**
 145  * cpuidle_remove_class_sysfs - remove CPU global sysfs attributes
 146  */
 147 void cpuidle_remove_class_sysfs(struct sysdev_class *cls)
 148 {
 149         sysfs_remove_group(&cls->kset.kobj, &cpuclass_attr_group);
 150 }
 151
 152 struct cpuidle_attr {
 153         struct attribute attr;
 154         ssize_t (*show)(struct cpuidle_device *, char *);
 155         ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
 156 };
 157
 158 #define define_one_ro(_name, show) \
 159         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 160 #define define_one_rw(_name, show, store) \
 161         static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
 162
 163 #define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
 164 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
 165 static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf)
 166 {
 167         int ret = -EIO;
 168         struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
 169         struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
 170
 171         if (cattr->show) {
 172                 mutex_lock(&cpuidle_lock);
 173                 ret = cattr->show(dev, buf);
 174                 mutex_unlock(&cpuidle_lock);
 175         }
 176         return ret;
 177 }
 178
 179 static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr,
 180                      const char * buf, size_t count)
 181 {
 182         int ret = -EIO;
 183         struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
 184         struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
 185
 186         if (cattr->store) {
 187                 mutex_lock(&cpuidle_lock);
 188                 ret = cattr->store(dev, buf, count);
 189                 mutex_unlock(&cpuidle_lock);
 190         }
 191         return ret;
 192 }
 193
 194 static struct sysfs_ops cpuidle_sysfs_ops = {
 195         .show = cpuidle_show,
 196         .store = cpuidle_store,
 197 };
 198
 199 static void cpuidle_sysfs_release(struct kobject *kobj)
 200 {
 201         struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
 202
 203         complete(&dev->kobj_unregister);
 204 }
 205
 206 static struct kobj_type ktype_cpuidle = {
 207         .sysfs_ops = &cpuidle_sysfs_ops,
 208         .release = cpuidle_sysfs_release,
 209 };
 210
 211 struct cpuidle_state_attr {
 212         struct attribute attr;
 213         ssize_t (*show)(struct cpuidle_state *, char *);
 214         ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
 215 };
 216
 217 #define define_one_state_ro(_name, show) \
 218 static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
 219
 220 #define define_show_state_function(_name) \
 221 static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
 222 { \
 223         return sprintf(buf, "%u\n", state->_name);\
 224 }
 225
 226 #define define_show_state_ull_function(_name) \
 227 static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
 228 { \
 229         return sprintf(buf, "%llu\n", state->_name);\
 230 }
 231
 232 #define define_show_state_str_function(_name) \
 233 static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
 234 { \
 235         if (state->_name[0] == '\0')\
 236                 return sprintf(buf, "<null>\n");\
 237         return sprintf(buf, "%s\n", state->_name);\
 238 }
 239
 240 define_show_state_function(exit_latency)
 241 define_show_state_function(power_usage)
 242 define_show_state_ull_function(usage)
 243 define_show_state_ull_function(time)
 244 define_show_state_str_function(name)
 245 define_show_state_str_function(desc)
 246
 247 define_one_state_ro(name, show_state_name);
 248 define_one_state_ro(desc, show_state_desc);
 249 define_one_state_ro(latency, show_state_exit_latency);
 250 define_one_state_ro(power, show_state_power_usage);
 251 define_one_state_ro(usage, show_state_usage);
 252 define_one_state_ro(time, show_state_time);
 253
 254 static struct attribute *cpuidle_state_default_attrs[] = {
 255         &attr_name.attr,
 256         &attr_desc.attr,
 257         &attr_latency.attr,
 258         &attr_power.attr,
 259         &attr_usage.attr,
 260         &attr_time.attr,
 261         NULL
 262 };
 263
 264 #define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
 265 #define kobj_to_state(k) (kobj_to_state_obj(k)->state)
 266 #define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
 267 static ssize_t cpuidle_state_show(struct kobject * kobj,
 268         struct attribute * attr ,char * buf)
 269 {
 270         int ret = -EIO;
 271         struct cpuidle_state *state = kobj_to_state(kobj);
 272         struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
 273
 274         if (cattr->show)
 275                 ret = cattr->show(state, buf);
 276
 277         return ret;
 278 }
 279
 280 static struct sysfs_ops cpuidle_state_sysfs_ops = {
 281         .show = cpuidle_state_show,
 282 };
 283
 284 static void cpuidle_state_sysfs_release(struct kobject *kobj)
 285 {
 286         struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
 287
 288         complete(&state_obj->kobj_unregister);
 289 }
 290
 291 static struct kobj_type ktype_state_cpuidle = {
 292         .sysfs_ops = &cpuidle_state_sysfs_ops,
 293         .default_attrs = cpuidle_state_default_attrs,
 294         .release = cpuidle_state_sysfs_release,
 295 };
 296
 297 static void inline cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
 298 {
 299         kobject_put(&device->kobjs[i]->kobj);
 300         wait_for_completion(&device->kobjs[i]->kobj_unregister);
 301         kfree(device->kobjs[i]);
 302         device->kobjs[i] = NULL;
 303 }
 304
 305 /**
 306  * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
 307  * @device: the target device
 308  */
 309 int cpuidle_add_state_sysfs(struct cpuidle_device *device)
 310 {
 311         int i, ret = -ENOMEM;
 312         struct cpuidle_state_kobj *kobj;
 313
 314         /* state statistics */
 315         for (i = 0; i < device->state_count; i++) {
 316                 kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
 317                 if (!kobj)
 318                         goto error_state;
 319                 kobj->state = &device->states[i];
 320                 init_completion(&kobj->kobj_unregister);
 321
 322                 ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj,
 323                                            "state%d", i);
 324                 if (ret) {
 325                         kfree(kobj);
 326                         goto error_state;
 327                 }
 328                 kobject_uevent(&kobj->kobj, KOBJ_ADD);
 329                 device->kobjs[i] = kobj;
 330         }
 331
 332         return 0;
 333
 334 error_state:
 335         for (i = i - 1; i >= 0; i--)
 336                 cpuidle_free_state_kobj(device, i);
 337         return ret;
 338 }
 339
 340 /**
 341  * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
 342  * @device: the target device
 343  */
 344 void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
 345 {
 346         int i;
 347
 348         for (i = 0; i < device->state_count; i++)
 349                 cpuidle_free_state_kobj(device, i);
 350 }
 351
 352 /**
 353  * cpuidle_add_sysfs - creates a sysfs instance for the target device
 354  * @sysdev: the target device
 355  */
 356 int cpuidle_add_sysfs(struct sys_device *sysdev)
 357 {
 358         int cpu = sysdev->id;
 359         struct cpuidle_device *dev;
 360         int error;
 361
 362         dev = per_cpu(cpuidle_devices, cpu);
 363         error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &sysdev->kobj,
 364                                      "cpuidle");
 365         if (!error)
 366                 kobject_uevent(&dev->kobj, KOBJ_ADD);
 367         return error;
 368 }
 369
 370 /**
 371  * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
 372  * @sysdev: the target device
 373  */
 374 void cpuidle_remove_sysfs(struct sys_device *sysdev)
 375 {
 376         int cpu = sysdev->id;
 377         struct cpuidle_device *dev;
 378
 379         dev = per_cpu(cpuidle_devices, cpu);
 380         kobject_put(&dev->kobj);
 381 }